Separation of suspended particulates from fluids is a common filtration engineering task. Solid, semi-solid or gel-like particulates may be suspended or carried in a gases or liquids in motion. Small water droplets, spray-mist, sea salt, dust etc, may be suspended in the ambient air, carried by wind or blown by ventilation systems. Fly ash and unburned coal dust may be exhausted in the hot fumes of industrial boilers and combustors. Intakes of water treatment systems, desalination systems may have sand and suspended silt in the raw water. Wastewater and storm water may also carry large quantities of suspended solids. Various chemical, petrochemical and pharmaceutical processes may have liquids that have suspended bubbles of insoluble liquids (emulsion droplets) or small blobs of coagulated matter mixed in with the carrying liquid. The present application has a solution for the problem of efficient separation of such particles and droplets from fluids by means of inertial separation. In inertial separation technologies, local acceleration is used to induce inertial forces to the suspended particles required for separation. The concentration of particles is low or close to zero in the filtrate stream and high in the concentrate stream. The efficiency of separation is commonly expressed as the ratio of particle concentration in filtrate stream over the particle concentration in the feed stream. There are several known inertial separation technologies. Demister vanes, marine vane separators, inertial spin or swirl tubes, tuyere separators, centrifuges, variety of cyclones, etc.
Cyclone separation technology is widely used for removal of particulate matter from fluids without the use of filters. Cyclones are devices that create high speed rotating flow—or spinning field of fluid—in a cylindrical and conical vessel by inducing the fluid tangentially to the circumference of the cylinder. Centrifugal force and gravity are used to separate mixtures of solids and fluids. Air flows in a spiral pattern, beginning at the top (wide end) of the cyclone and ending at the bottom (narrow) end before exiting the cyclone in a straight stream through the center of the cyclone and out at the top. Larger and denser particles in the rotating stream have too much inertia to follow the curvature of the stream and strike the outside wall, falling then to the bottom of the cyclone where they can be removed. In a conical system, as the rotating flow moves towards the narrow end of the cyclone the radius of the stream curvature is reduced, separating smaller and smaller particles. Larger particles will be removed with a greater efficiency and smaller particles with a lower efficiency. The disadvantage of the currently known cyclone technology is that it has limited minimum streamline curvature (i.e. how small the curvature can be). The streamline curvature is largely defined by the radius of the cylindrical portion of the cyclone. As smaller curvature generally results in better separation efficiency, therefore the current cyclone technology has limited efficiency because the curvature of the cyclone is limited to the radius of its cylinder. The present application has improved separation efficiency over the current cyclones.
Various separation screens are also widely used in the field of liquid and gas filtration. There are several known inertial separator technologies such as demister vanes, marine vane separators, tuyere separators, water intake screens, etc. Few of these recently developed separator systems employ sweeping flow to facilitate and improve the separation of suspended matter. The sweeping flow is tangential to the surface of the separator while the pass-through flow is perpendicular to the surface. These recently introduced sweeping flow technologies utilize wedge wire screens for inertial separation, such as described in US20100224570. Wedge shaped wire screens are preferred for their low-maintenance operation.
The present application is the continuation of the inertial separation concept described in the Patent Application titled “Wedge Bar for Inertial Separation” U.S. Ser. No. 12/924,003 Asymmetrical separators elements are utilized, promoting small curvature accelerated flow across the linear gaps of the screen—separated from the flow sweeping the face side of the screen.